Characteristics of minerals in Slovenian marbles

Common rock-forming and accessory minerals in marbles from various localities in Slovenia were studied using scanning electron microscopy with energy dispersive spectroscopy (SEM/EDS). Minerals and their chemical composition were identified in order to verify the variability of mineral assemblages in marbles from different localities in Slovenia. The analysis showed that marbles from Košenjak are the most mineralogically diverse, followed by Pohorje and finally Strojna marbles. Common rock-forming minerals calcite and dolomite are more abundant in Pohorje marbles where calcite contains higher levels of magnesium but no strontium and iron as compared with Strojna and Košenjak marbles. Accessory minerals like quartz, mica, titanite, apatite, rutile, zircon, chlorite group minerals, kaolinite and iron oxides/hydroxides were found in marbles from all localities. Clinopyroxene, amphibole, epidote and smectite group minerals, talc, tungsten-bearing ilmenorutile, psilomelane and bismuth oxides/carbonates, were observed only in marbles from Pohorje, while tourmaline and allanite group minerals, thorite or huttonite, chalcopyrite and synchysite group minerals were detected in marbles from Košenjak and Strojna. Variations in mineral assemblages in marbles from different locations are likely a consequence of different sedimentary environment and conditions and metamorphic grade of marble. These differences indicate that marbles from Košenjak and Strojna are genetically different from those from Pohorje and probably reflect mineral composition of the protolith. Thus, they enable rough distinction between more distant locations, but not between individual sub-localities.